The Study On The Control Techniques And Monitor System Design For The Double-Fed Induction Generator System

In recent years, with the lack of general energy resources and the increasing worsening of environment, it is provided with very important meanings to abate energy lack by using renewable energy resource. By virtue of its outstanding merits, wind power has drawn great attention in exploiting renewable energy resource, and the wind power technology has become tremendous scholars' research hotspot. The Variable Speed Constant Frequency (VSCF) wind power generation system using Doubly-Fed Induction Generator (DFIG) improves the utilization ratio of wind power. The system can adjust the active and reactive power separately, and improves the stability of electric power system. The key technology of VSCF doubly fed induction generator system is studied in this dissertation.This dissertation firstly analyzes the wind turbine and DFIG operation principle, including mathematic model of DFIG and DFIG operation characteristics. A general control model based on stator flux oriented vector control is established to realize the speed control of DFIG and decoupled control of the active and reactive power, which bottomed for the implementation of tracking maximum wind energy strategy.Secondly, the characteristic of dual PWM converter, which is used for DFIG excitation, is discussed. The control strategy of grid-side converter, the function of which is to adjust the in put power factor at grid side and to control DC bus voltage is proposed on the basis of the field oriented vector control.Then, Simulation study is carried out on the platform of MATLAB/SIMULINK to validate the proposed strategy. Simulation results indicate that the system has excellent dynamic performance. In addition to this, the results also indicate the grid side converter possesses many advantages, such as low harmonic, high power factor, fast dynamic response and energy bidirectional flow, could satisfy the demand of DFIG excitation. Finally, an embedded DFIG monitoring system based on S3C2410A and RT-Linux operation system is presented, covering the design work of peripheral circuit, the development of Linux device driver, the research of maximum power point tracking based on hill-climb searching algorithm, and the implement of the embedded GUI through the QT/Embedded.